I've been shooting hiking videos for 25 years. My current project is a doc on hiking the 3,000 mile Continental Divide Trail. Last summer I did a 110-mile section using the Sony HC-3 with its rather useful blue tooth microphone arrangement. However, this summer I'm faced with trying to reduce my pack weight while maintaining video standards, if possible.
My question to the HD1/2 community of users is this--given that my shooting is under daylight conditions mostly, do you think that Sanyo footage would be equivalent in looks to HC3 footage? Or are the discrepancies so noticeable, especially on vista-type long shots, that I would be advised to stick with the Sony and just suck up the extra weight?

If I've learned anything in 60 years of photography, professional and otherwise, it is that quality is in the eye of the beholder and the beholding has to be done in realistic circumstances.
What do you do with your video? Do you edit it a lot? Etc.
I have found the HD1 satsifactory for stills and video watched on a 60 inch HDTV. I have the HD2 on order. I have looked at the AVCHD cameras and was disappointed -- nothing there to justify a bigger, heavier and much more expensive camera, let alone a format that so far can't be edited easily.
Having become used to working with SD cards, I am too lazy and impatient to go back to tape.
The only way you will really know whether the Sanyos meet your needs is to buy one from a store that will take it back and try it out. No amount of advice from others or technical chit-chat can substitute for actual use under your conditions.

The Sanyos do have an external mike input, but don't have a headphone output. There is a level adjustment for external mikes, but you would have to check it on playback with the tiny speaker.
I liked the Canon HV10 the best of all the newer HD cameras. It is quite small and seems to have excellent picture quality. What stopped me was going back to tape.

HDV records 1080 video in 1440x1080 resolution, and many Sony HDV cameras have CCD size of 960x1080. Interlaced frame makes the vertical resolution only half effective for moving images so it's more like 960x540, but with higher temporal resolution of course. What makes HDV winner over mpeg4 based 720p is the datarate. Even the old mpeg2 25mbps is much better than mpeg4 with 9mbps.

I don't expect too much of improvement of HD2's 720p because it's the same codec with same bitrate. But I hope they got rid of diagonal jaggies and gave it wider dynamic range. Their claim of better low-light performance gives me a bit of hope.

"Some shooters will like the low rate because it is close to 24fps, thereby providing what they consider a 'filmic' look."

"Others will dislike the look, as rapidly moving objects — or non-moving objects when one pans too quickly — appear as 'double objects.'

"The name for this visual artifact is 'eye tracking,' and it is generated within our eyes.

"The double images are not recorded to tape."

"Our eyes create the artifact from moving objects within a series of images where every frame is repeated — as it is when 720p30 is converted by the camcorder to 720p60 for display. (Just as when film is projected using a double-bladed shutter.)"

"Although the artifact can't be eliminated, you can minimize it by locking the shutter-speed at 1/60 second — a speed equivalent to a film camera set to a 180-degree shutter."

"JVC recommends locking a 1/30 shutter speed that masks the artifact by creating so much motion blur — from the very slow shutter — that the two objects blur into one."

"While I prefer the former solution, my testing showed that any shutter speed from 1/30 to 1/60 second is equally acceptable."

I was one of those shooters who found the 720p video from the JVC JY-HD10 to be absolutely unacceptable because of this "eye tracking" issue, which is precisely the problem that puzzled me about that camcorder from day one.

I didn't find this article until it was too late.

I wish I could have found the article sooner.

But since the SANYO HD2 also is confined to 30 frames per second, it might exhibit the same problem.

Ironically, the camcorder that now has me interested is another JVC model, this forthcoming GZ-HD7: http://tinyurl.com/2v75v4

The JVC GZ-HD7 does look interesting. I prefer the SD card medium (which Sanyo and Panasonic are using) to the hard drive. The cameras can be smaller and lighter, with fewer moving parts. Extra cards are very portable and you can download into any card reader without having to hook up the camera.

We don't know exactly what format the JVC will record to. We do know that it will cost almost three times as much as the Sanyo and is bigger and heavier. As usual, whether that is worth it depends entirely on what you are trying to accomplish.

The thing that is most interesting about the forthcoming JVC model -- in my view -- is the lens.

Some shooters using fairly expensive HDV camcorders have noted that if they switch out the stock lens with a higher quality lens, it vastly improves the picture to the point where visual issues they formerly *thought* were HDV encoding issues were -- in reality -- issues related to using a lesser-quality lens.

Interesting discussion. I appreciate all the various opinions. As someone else stated, the new .95 pound Canon HD10 with only a built-in mic was a major disappointment. When I as the cameraman am also the hiker and am carrying all my other gear as well, ounces matter. That's why I didn't carry the wide-angle lens for the Sony HC-3 last summer--it weighed almost 8 ounces by itself. So regarding the Canon, to get good audio would have required lugging separate audio recording devices--too heavy.
Even the Sanyo with its SD card presents a problem--how to easily download data once you get to a town to resupply? (Carrying many cards is too expensive.) Tape is easy to deal with--just pick up more at Wal-Mart or from your own resupply box you mail to yourself at the local PO.
As you might guess, the sort of hikes I'm describing are long-distance, many hundreds and even thousands of miles over the course of months. Like the Appalachian and Pacific Crest Trails. Going home is not an option.

I backpack, too, so I really appreciate the concern about weight and size, as well as the importance of acquiring decent quality audio. Given the absence of any palm-size high-def camera with both audio inputs and outputs, how about carrying along a small outboard recorder like the Zoom H4? I know it adds another 5 ounces of weight and takes up room in the pack, but isn't the capability of getting decent sound worth it? Of course, I'm the same fool who once stuck 25 pounds of camera gear on his back for a solo week-long trek through the Grand Canyon. I had plenty of time to contemplate the error of my ways on that trip.

I guess I was hoping Panasonic would instead give us a miniature 3CCD AVCHD camcorder -- but not forget the microphone input -- as they did with the standard definition memory card camcorder, the SDR-S150: http://tinyurl.com/yu2kcf

If they could give us a microphone input into a camcorder as small as the SDR-S150 -- but high definition instead of standard definition -- that would be almost perfect for backpackers like me.